Name: gene interaction maps in epistasis
Uploaded: 2023-04-30T10:14:33.000Z
Duration: 1 min 9 s
Channel: JoVE

Eine gegensätzliche Beziehung zwischen zwei Genen ist die Epistase, bei der ein Gen die Expression eines anderen überdeckt oder verändert. Man sagt, dass das beeinflussende Gen epistatisch zu dem Gen ist, das maskiert wird.
Zum Beispiel bestimmt ein Gen, das für das Tyrosinase-verwandte Protein 1 oder TYRP1 kodiert, die Fellfarbe von Hunden – schwarz oder braun.
Ein weiteres Gen, Tyr, kodiert für das Enzym Tyrosinase, das für die Pigmentierung bei Tieren verantwortlich ist. Eine Mutation in diesem Gen kann das Fehlen von Pigment verursachen, was zu einem Albino-Hund führt, der keine Färbung aufweist.
Die Reihenfolge, in der diese beiden Gene exprimiert werden, kann durch einen Epistase-Test bestimmt werden.
Wenn eine Mutation im Tyr-Gen einen Albino-Hund hervorbringt, der noch das Wildtyp-TYRP1-Gen besitzt, kann daraus geschlossen werden, dass das Tyr-Gen die Wirkung des TYRP1-Gens maskiert. Dies würde bedeuten, dass Tyr epistatisch zu TYRP1 ist.

<ol>
	<li>Michels, C.A. (2002). Epistase-Analyse. In Genetische Techniken für die biologische Forschung, C.A. Michels (Hrsg.). https://doi.org/10.1002/0470846623.ch6</li>
	<li>Bernstein, Harris, Henry C. Byerly, Frederic A. Hopf und Richard E. Michod. "Genetische Schäden, Mutationen und die Evolution des Geschlechts." Science 229, Nr. 4719 (1985): 1277-1281.</li>
</ol>

epistaseanalyse

Epistasis Analysis

Obwohl Mendel sieben voneinander unabhängige Merkmale bei Erbsen auswählte, um die Genverteilung zu studieren, involvieren die meisten Merkmale multiple Geninteraktionen, die ein Spektrum von Phänotypen erzeugen. Wenn die Interaktion verschiedener Gene oder Allele an unterschiedlichen Orten einen Phänotyp beeinflusst, spricht man von Epistase. Epistase beinhaltet oft, dass ein Gen die Expression eines anderen maskiert oder stört (antagonistische Epistase). Epistase tritt häufig auf, wenn verschiedene Gene Teil desselben biochemischen Wegs sind. Die Expression eines Gens kann von einem Genprodukt im selben biochemischen Weg abhängen.

Epistatische Analyse

Die Untersuchung epistatischer Interaktionen ermöglicht es Forschern, die funktionale Beziehung zwischen Genen, die Anordnung der Gene in einem Weg und wie unterschiedliche Allele quantitativ Phänotypen beeinflussen, zu bestimmen. Betrachtet man eine biochemische Reaktion, die von mehreren Proteinen katalysiert wird, die von verschiedenen Genen kodiert werden, können die beteiligten Gene andere Gene im selben biochemischen Weg maskieren oder hemmen, ein Phänomen, das als Epistase bezeichnet wird. Solche Gene werden als in einer Epistasegruppe befindlich betrachtet. Durch die Analyse der epistatischen Beziehung zwischen verschiedenen Genen können Wissenschaftler eine Funktionsreihenfolgekarte erstellen, die die Abfolge von Ereignissen und beteiligten Genen in einem Weg zeigt. Dieser Prozess wird als epistatische Analyse bezeichnet. Die für die epistatische Analyse ausgewählten Allele müssen deutliche Phänotypen aufweisen.

Seit der Einführung des Konzepts der Epistase wurde zunehmend deutlich, dass die meisten biologischen Systeme viele genetische Elemente umfassen, die auf vielfältige und komplexe Weise miteinander interagieren.

Epistaseanalyse

Obwohl Mendel sieben nicht verwandte Merkmale in Erbsen auswählte, um die Gensegregation zu untersuchen, beinhalten die meisten Merkmale mehrere Geninteraktionen, die ein Spektrum von ...

Education

Lehre

JoVE Core

Molecular Biology

Molekularbiologie

Unit 2

Einheit 2

Analyzing Gene Expression and Function

Analyse von Genexpression und -funktion

KEY TERMS AND CONCEPTS

KERNBEGRIFFE UND KONZEPTE

gene interaction maps in epistasis

Gene interaction maps in epistasis show how different genes work together to shape a phenotype. In epistasis, the interaction of genes or alleles at different locations affects the final trait. This often happens when one gene masks or interferes with the expression of another gene.

Epistasis is common when genes are part of the same biochemical pathway. In that case, the expression of one gene can depend on a gene product made earlier in the pathway. Genes that mask or inhibit other genes in the same pathway are considered part of one epistasis group.

Epistatic analysis uses these interactions to reveal how genes are related. Scientists can use it to identify the functional relationship between genes, determine the order of genes in a pathway, and see how different alleles affect phenotypes in a quantitative way. When multiple proteins encoded by different genes take part in a biochemical reaction, epistatic analysis can help build an order-of-function map that shows the sequence of events and the genes involved.

To compare genes in this way, the alleles chosen for analysis must have distinct phenotypes. Since epistasis was first described, it has become clear that many biological systems include genetic elements that interact in complex ways. These interactions help explain why many traits do not follow simple single-gene patterns.

Gene Interaction Maps in Epistasis

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epistasis analysis

Gene interaction maps in epistasis show how different genes work together to shape a phenotype. In epistasis, the interaction of genes or alleles at different locations affects the final trait. This often happens when one gene masks or interferes with the expression of another gene. Epistasis is common when genes are part of the same biochemical pathway. In that case, the expression of one gene can depend on a gene product made earlier in the pathway. Genes that mask or inhibit other genes in...

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key terms and concepts

Explore how epistasis reveals gene interactions, pathway order, and phenotype changes through epistatic analysis in high school biology.

Gene Interaction Maps in Epistasis | JoVE K12

molecular biology

JoVE Core Molecular Biology veranschaulicht die molekularen Prozesse der Zelle in prägnanten animierten Video-Lektionen. In Videos von Wissenschaftlern in Aktion wird die Anwendung dieser Konzepte zusätzlich durch reale Experimente in modernen Laboren demonstriert.

Gene Interaction Maps in Epistasis

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